Breeding biology of Icelandic thrushes

• Main Author: Hulda Elísabet Harðardóttir 1994-
• Other Authors: Háskóli Íslands
• Format: Thesis
• Language: English
• Published: 2019
• Subjects: Líffræði; Skógarþröstur; Svartþröstur; Varp; Fossvogur; Reykjavík; Iceland
• Online Access: http://hdl.handle.net/1946/33235

This thesis integrates in three separate chapters some aspects of the breeding biology of the Eurasian redwing (Turdus iliacus coburni) and the Eurasian blackbird (T. merula). The redwing has been breeding in Iceland for centuries while the blackbird colonized between 1990-2000 and is still a relatively scarce breeding bird outside SW-Iceland. Both species are understudied in Iceland despite many valuable research questions, especially on interactions between the species due to the recent colonisation of the blackbird. The study was conducted in two consecutive summers in 2017 and 2018, in Fossvogur cemetery located centrally in Reykjavik Iceland. The first chapter focuses on various aspects of their breeding biology including timing, nest site selection and breeding success. The aims were to shed light on their breeding biology in Iceland and to see how well these species do when competing for resources in the same habitat. The second chapter focuses on methods in estimating breeding population densities of Icelandic thrushes. The aims were to see if using point counts of singing males would give a reliable estimate of density compared to the minimum number of nests in the area. The third chapter focuses on the prevalence of blood parasites in Icelandic redwings. The aims were to see if blood parasites were present in the blood of Icelandic redwings and look for evidence of whether birds get infected within Iceland. Þessi ritgerð tengir í þremur köflum saman þætti í varplíffræði skógarþrasta (Turdus iliacus coburni) og svartþrasta (T. merula). Skógarþröstur hefur orpið á íslandi svo öldum skiptir en stöðugur stofn af svartþröstum hefur aðeins orpið hér síðan á árunum 1990-2000. Rannsóknum á báðum tegundum er ábótavant á Íslandi og sérstaklega samspili þeirra á milli frá landnámi svarþrastarins. Rannsóknin var framkvæmd á tveimur árum, sumrin 2017 og 2018 í Fossvogskirkjugarði í Reykjavík. Fyrsti kaflinn leggur áherslu á ýmsa þætti í varplíffræði þeirra, þar með talið lengd varptíma, val á hreiðurstæði og ...